Asymmetric Acid-Catalyzed Meerwein−Ponndorf−Verley−Aldol Reactions of Enolizable Aldehydes
摘要:
A highly, stereo- and regioselective Meerwein - Ponndorf - Verley - Aldol etherification process of enolizable aldehydes is described. This new transformation is catalyzed by trifluoroacetic acid. The method also allows cross-aldol reactions with alpha-branched enolizable aldehydes and thus provides access to defined configured quaternary stereogenic centers.
A highly, stereo- and regioselective Meerwein - Ponndorf - Verley - Aldol etherification process of enolizable aldehydes is described. This new transformation is catalyzed by trifluoroacetic acid. The method also allows cross-aldol reactions with alpha-branched enolizable aldehydes and thus provides access to defined configured quaternary stereogenic centers.
Acid-catalyzed aldol-Meerwein–Ponndorf–Verley-etherification reactions—access to defined configured quaternary stereogenic centers
作者:Andrea Seifert、Kerstin Rohr、Rainer Mahrwald
DOI:10.1016/j.tet.2011.11.069
日期:2012.1
A novel asymmetric aldol-reduction-etherification process of aliphatic enolizable aldehydes is described. The intermediately formed aldol adducts-beta-hydroxyaldehydes-were reduced and transformed into the corresponding 1,3-diol ethers by external secondary alcohols at the same time. Thus, with the help of chiral secondary alcohols an access to optically active 1,3-diol ether is given. Furthermore, asymmetric cross-aldol-Meerwein-Ponndorf reactions of enolizable aldehydes can also be realized under these reaction conditions. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.